Activity of ceftaroline against selected clinical isolates of Staphylococcus aureus from the Canadian Bacterial Sentinel Network

Abstract number: P938

Objective: To evaluate the activities of ceftaroline against contemporary clinical isolates of Staphylococcus aureus collected in Canadian medical centres as part of the Canadian Bacterial Surveillance Network (CBSN). Ceftaroline is a novel, parenteral cephalosporin exhibiting bactericidal activity against Gram-positive organisms, including methicillin-susceptible and -resistant S. aureus (MSSA and MRSA), and common Gram-negative pathogens. CBSN has conducted cross-Canada S. aureus surveillance since 1987.

Methods: Susceptibility testing for ceftaroline and comparator antimicrobials was performed using CLSI broth microdilution methods on 591 isolates obtained from the CBSN (19992009) supplemented with 42 strains from the Network of Antimicrobial Resistance in S. aureus (NARSA) program. Community-acquired (CA) and hospital-acquired (HA) MRSA, MSSA, and vancomycin-intermediate S. aureus (VISA) isolates were included. Where possible, the most recent CBSN isolates were selected; number of isolates per year (year/n): 1999/1; 2002/92; 2003/62; 2004/40; 2005/56; 2006/25; 2007/195; 2008/110; 2009/10.

Conclusions: Ceftaroline demonstrated potent in vitro activity against selected contemporary CBSN and NARSA S. aureus isolates, including strains with resistance to methicillin and/or reduced susceptibility to vancomycin. S. aureus resistance to commonly used antimicrobials did not adversely affect ceftaroline activity. These data highlight the potential utility of ceftaroline in treating S. aureus infections, including MSSA, MRSA, and VISA, in both community and hospital settings.

n

Cumulative % at ceftaroline MIC(mg/L)

MIC(mg/L)

0.12

0.25

0.5

1

2

MIC50

MIC90

All

633

2.1

17.9

75.8

95.1

100

0.5

1

CA-MRSA

214

-

1.8

89.7

99.5

100

0.5

1

CA-MSSA

86

14

98.8

100

-

-

0.25

0.25

HA-MRSA

275

-

2.2

60.4

90.2

100

0.5

1

HA-MSSA

14

7.1

85.7

100

-

-

0.25

0.25

MR-VISA

39

-

2.6

43.6

92.3

100

1

1

MS-VISA

5

-

100

-

-

-

-

-

MR = methicillin resistant; MS = methicillin susceptible.

Session Details

Date:

10/04/2010

Time:

00:00-00:00

Session name:

Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases